Method and apparatus for controlling ue context in wireless communication system

Abstract

A method and an apparatus for controlling user equipment (UE) context between a plurality of nodes are provided. The method includes transmitting, to a second node, a first message to request a user equipment (UE) context update, receiving, from the second node, a second message indicative of a completion of the UE context update or a third message indicative of a failure of the UE context update in response to the transmission of the first message, and determining whether to retransmit the first message to the second node based on the reception of the second message or the third message. The procedure of the UE context update may be initiated by the transmission of a message to request an operation of the UE context update to be performed between a UE and a third node from the second node to the third node.

What is claimed is: 
     
         1 . A method performed by a distributed unit (DU) of a next generation node B (gNB) in a wireless communication system, the method comprising:
 transmitting, to a central unit (CU) of the gNB, a user equipment (UE) context modification required message to request a UE context modification; and   receiving, from the CU, a UE context modification refuse message indicating that the UE context modification is unsuccessful based on an evolved node B (eNB),   wherein the eNB and the gNB are configured in a dual connectivity,   wherein the UE context modification required message includes a gNB-CU UE identifier (ID) for identifying a UE within the CU, a gNB -DU UE ID for identifying a UE within the DU, and a resource coordination transfer container,   wherein the resource coordination transfer container includes a secondary gNB (SgNB) resource coordination information element (IE) for the eNB,   wherein the SgNB resource coordination IE includes information on a new radio (NR) cell global identity (CGI) and coordination information, and   wherein the UE context modification refuse message includes the gNB-CU UE ID, the gNB-DU UE ID, and information on a cause of the unsuccessful UE context modification.   
     
     
         2 . The method of  claim 1 ,
 wherein the CU is associated with a radio resource control (RRC) layer and a packet data convergence protocol (PDCP) layer, and   wherein the DU is associated with a radio link control (RLC) layer, a medium access control (MAC) layer, and a physical (PHY) layer.   
     
     
         3 . The method of  claim 1 , wherein the UE context modification refuse message is based on a modification refuse message transmitted from the eNB to the CU of the gNB. 
     
     
         4 . The method of  claim 1 ,
 wherein the DU of the gNB and the CU of the gNB are connected through a F1 interface, and   wherein the CU of the gNB and the eNB are connected through an X2 interface.   
     
     
         5 . The method of  claim 1 , wherein the UE context modification required message includes identification information on one or more data radio bearers (DRBs) to be modified and downlink (DL) user plane (UP) tunnel (TNL) information. 
     
     
         6 . A method performed by a central unit (CU) of a next generation node B (gNB) in a wireless communication system, the method comprising:
 receiving, from a distributed unit (DU) of the gNB, a user equipment (UE) context modification required message to request a UE context modification; and   transmitting, to the DU of the gNB, a UE context modification refuse message, in case that the UE context modification is unsuccessful based on an evolved node B (eNB),   wherein the eNB and the gNB are configured in a dual connectivity,   wherein the UE context modification required message includes a gNB-CU UE identifier (ID) for identifying a UE within the CU, a gNB-DU UE ID for identifying a UE within the DU, and a resource coordination transfer container,   wherein the resource coordination transfer container includes a secondary gNB (SgNB) resource coordination information element (IE) for the eNB,   wherein the SgNB resource coordination IE includes information on a new radio (NR) cell global identity (CGI) and coordination information, and   wherein the UE context modification refuse message includes the gNB-CU UE ID, the gNB-DU UE ID, and information on a cause of the unsuccessful UE context modification.   
     
     
         7 . The method of  claim 6 ,
 wherein the CU is associated with a radio resource control (RRC) layer and a packet data convergence protocol (PDCP) layer, and   wherein the DU is associated with a radio link control (RLC) layer, a medium access control (MAC) layer, and a physical (PHY) layer.   
     
     
         8 . The method of  claim 6 , wherein the UE context modification refuse message is based on a modification refuse message transmitted from the eNB to the CU of the gNB. 
     
     
         9 . The method of  claim 6 ,
 wherein the DU of the gNB and the CU of the gNB are connected through a F1 interface, and   wherein the CU of the gNB and the eNB are connected through an X2 interface.   
     
     
         10 . The method of  claim 6 , wherein the UE context modification required message includes identification information on one or more data radio bearers (DRBs) to be modified and downlink (DL) user plane (UP) tunnel (TNL) information. 
     
     
         11 . A distributed unit (DU) of a next generation node B (gNB) in a wireless communication system, the DU of the gNB comprising:
 memory configured to store instructions; and   at least one transceiver; and   at least one processor,   wherein the instructions cause, when executed by the at least one processor, the DU to:
 transmit, to a central unit (CU) of the gNB via the at least one transceiver, a user equipment (UE) context modification required message to request a UE context modification, and 
 receive, from the CU of the gNB via the at least one transceiver, a UE context modification refuse message indicating that the UE context modification is unsuccessful based on an evolved node B (eNB), 
   wherein the eNB and the gNB are configured in a dual connectivity,   wherein the UE context modification required message includes a gNB-CU UE identifier (ID) for identifying a UE within the CU, a gNB -DU UE ID for identifying a UE within the DU, and a resource coordination transfer container,   wherein the resource coordination transfer container includes a secondary gNB (SgNB) resource coordination information element (IE) for the eNB,   wherein the SgNB resource coordination IE includes information on a new radio (NR) cell global identity (CGI) and coordination information, and   wherein the UE context modification refuse message includes the gNB-CU UE ID, the gNB-DU UE ID, and information on a cause of the unsuccessful UE context modification.   
     
     
         12 . The DU of the gNB of  claim 11 ,
 wherein the CU is associated with a radio resource control (RRC) layer and a packet data convergence protocol (PDCP) layer, and   wherein the DU is associated with a radio link control (RLC) layer, a medium access control (MAC) layer, and a physical (PHY) layer.   
     
     
         13 . The DU of the gNB of  claim 11 , wherein the UE context modification refuse message is based on a modification refuse message transmitted from the eNB to the CU of the gNB. 
     
     
         14 . The DU of the gNB of  claim 11 ,
 wherein the DU of the gNB and the CU of the gNB are connected through a F1 interface, and   wherein the CU of the gNB and the eNB are connected through an X2 interface.   
     
     
         15 . The DU of the gNB of  claim 11 , wherein the UE context modification required message includes identification information on one or more data radio bearers (DRBs) to be modified and downlink (DL) user plane (UP) tunnel (TNL) information. 
     
     
         16 . A central unit (CU) of a next generation node B (gNB) in a wireless communication system, the CU of the gNB comprising:
 memory configured to store instructions; and   at least one transceiver; and   at least one processor,   wherein the instructions cause, when executed by the at least one processor, the DU to:
 receive, from a distributed unit (DU) of the gNB via the at least one transceiver, a user equipment (UE) context modification required message to request a UE context modification, and 
 transmit, to the DU of the gNB via the at least one transceiver, a UE context modification refuse message in case that the UE context modification is unsuccessful based on an evolved node B (eNB), 
   wherein the eNB and the gNB are configured in a dual connectivity,   wherein the UE context modification required message includes a gNB-CU UE identifier (ID) for identifying a UE within the CU, a gNB-DU UE ID for identifying a UE within the DU, and a resource coordination transfer container,   wherein the resource coordination transfer container includes a secondary gNB (SgNB) resource coordination information element (IE) for the eNB,   wherein the SgNB resource coordination IE includes information on a new radio (NR) cell global identity (CGI) and coordination information, and   wherein the UE context modification refuse message includes the gNB-CU UE ID, the gNB-DU UE ID, and information on a cause of the unsuccessful UE context modification.   
     
     
         17 . The CU of the gNB of  claim 16 ,
 wherein the CU is associated with a radio resource control (RRC) layer and a packet data convergence protocol (PDCP) layer, and   wherein the DU is associated with a radio link control (RLC) layer, a medium access control (MAC) layer, and a physical (PHY) layer.   
     
     
         18 . The CU of the gNB of  claim 16 ,
 wherein the UE context modification refuse message is based on a modification refuse message transmitted from the eNB to the CU of the gNB.   
     
     
         19 . The CU of the gNB of  claim 17 ,
 wherein the DU of the gNB and the CU of the gNB are connected through a F1 interface, and   wherein the CU of the gNB and the eNB are connected through an X2 interface.   
     
     
         20 . The CU of the gNB of  claim 16 ,
 wherein the UE context modification required message includes identification information on one or more data radio bearers (DRBs) to be modified and downlink (DL) user plane (UP) tunnel (TNL) information.